1. Field of the Invention
The present invention relates to an image display device having for example a graphical user interface (GUI), more particularly relates to an image display device provided with functions of adjusting the color of an image.
2. Description of the Related Art
In an image display device, in order to display a more preferred quality of image, a user sometimes adjusts the image, that is, handles the image. Specifically, an image display device has several adjustment functions such as color conversion, gamma adjustment, and sharpness adjustment (refer to for example Japanese Unexamined Patent Publication (Kokai) No. 2000-101533). When adjusting an image display device, only the adjusted result is displayed. There is no function enabling discrimination of which pixels changed from an input image.
Some image processing devices designed for broadcasting stations control the image display devices from the outside or are connected to the input portions of the image display devices for image processing. Some of these enable discrimination of the adjusted pixels on external terminals.
In the adjustment of the image display device, only the adjusted result has been displayed. There has never been a function enabling discrimination of which pixels changed from the input image, and no image display device enabled discrimination of the adjusted pixels by itself.
The user of an image display device sometimes wants to visually compare the part of the picture which was image processed and the part of the picture not image processed. With the adjustment device at the outside of the image display device, it is necessary to instruct (input) the part of the picture to be image processed and the part of the picture not to be image processed using an external device. In that case, it is necessary to later adjust the instructions (input information) while looking at the displayed processing result of the image display device.
As explained above, the image display device has several adjustment functions such as color conversion, gamma adjustment, and sharpness adjustment. A user sometimes desires to learn the pixels changed by using the adjustment functions.
Further, in color adjustment up to now, white balance adjustment was mainly used for the adjustment. “White balance adjustment” is adjustment of the balance of the three primary colors of R, G, and B. Therefore, when adjusting the colors so as for example to make the sky bluer, make a lawn greener, or make skin color redder, if focusing on just those colors, adjustment to the preferred colors is possible. However, even colors which must not originally be changed are affected by the adjustment, so the overall color balance collapses. Further, since the adjusted colors and ranges cannot be identified, even if adjusting the colors while viewing the picture, it is difficult to visually determine which parts of the colors have changed and the range of their effect. In practice, skill becomes necessary in order to reproduce the preferred color. There are however limits to improvement of this skill.